Segment Information - Revenue by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 8,269	$ 8,303	$ 16,149	$ 16,131
Operating Segments
Segment Reporting Information [Line Items]
Revenue	8,269	8,303	16,149	16,131
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	2,801	3,139	5,539	5,974
Operating Segments | Latin America
Segment Reporting Information [Line Items]
Revenue	1,115	919	2,107	1,790
Operating Segments | Europe/CIS/Africa
Segment Reporting Information [Line Items]
Revenue	1,896	1,784	3,602	3,496
Operating Segments | Middle East & Asia
Segment Reporting Information [Line Items]
Revenue	2,452	2,362	4,790	4,662
Eliminations & other
Segment Reporting Information [Line Items]
Revenue	$ 5	$ 99	$ 111	$ 209